Time‐resolved fluorescence studies on the formation and decomposition of the aromatic hydrocarbon‐aliphatic amine exciplex in solution

Fluorescence rise and decay processes were measured and rate parameters were determined for the pyrene‐tri‐n‐butylamine and pyrene‐N,N‐diethylaniline exciplex system in various solvents. An additional activation energy over that for the diffusional motion appears necessary for both exciplex formation and the deactivating quenching processes in the case of the pyrene‐tri‐n‐butylamine system. The rate‐determining step for these processes is electron transfer in the encounter collision leading to the nonrelaxed electron transfer state.